JPS6354152B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a canned motor pump that handles high temperature liquid.

Generally, the heat-resistant temperature of a motor is limited to 220° C. even in the case of a motor with conventional class C insulation, and the liquid temperature that can be introduced into this type of canned motor must be kept several tens of degrees lower than the above temperature. For this reason, 180
Conventional canned motor pumps that handle high-temperature liquids at temperatures above .degree. C. usually employ a water-cooling system as shown in FIG.

That is, in the canned motor pump shown in FIG. 1, a pump section 10 and a motor section 12 are connected via an adapter 14 in order to thermally separate them.
This adapter 14 is provided with a pressure equalizing hole 18 to prevent cavitation of the auxiliary impeller 16, and communicates the area where the pressure is increased by the main impeller 20 with the rotor chamber 22, thereby pressurizing the rotor chamber 22 side. In this case, since the pressure equalizing hole 18 is a small hole, the flow of liquid from the pump section 10 to the motor section is reduced, so in order to lubricate the bearings and cool the motor, the outer circumferential wall of the stator assembly 24 is A heat exchanger 26 is provided, and an auxiliary impeller 16 provided in the rotor chamber 22 for the heat exchanger 26 constitutes a circulation system for the liquid in the motor section 12. Therefore, the circulation of liquid within the motor section 12 is as follows. First, the liquid pressurized by the auxiliary impeller 16 is
It is introduced into the built-in pipe 30 of the heat exchanger 26 through the first circulation tube 28, where it is cooled by cooling water, and then through the second circulation tube 32 and the rear bearing housing 32. It is supplied into the rotor chamber 22. In this manner, fluid supplied into the rotor chamber 22 through the rear bearing housing 32 flows through the gap between the stator can 38 of the stator assembly 24 and the rotor can 42 of the rotor assembly 40 while lubricating the rear bearing 36. to absorb heat from the motor. By cooling the motor, the liquid whose temperature has increased by several degrees Celsius lubricates the front bearing 44 and returns to the suction portion of the auxiliary impeller 16 to repeat the circulation. In addition,
The cooling water introduced into the heat exchanger 26 cools the circulating fluid flowing through the circulation tubes 28 and 32 and simultaneously cools the stator assembly 24.
The motor is configured to be cooled using the outer circumferential wall of the motor as a heat transfer surface.

In the conventional canned motor pump configured in this manner, a considerable amount of the heat generated by the motor and the thermal energy of the handled liquid is lost to the cooling water, resulting in a very large heat loss. In addition, not only do the heat exchangers and their piping, as well as the ancillary equipment for supplying and discharging cooling water and water cutoff alarms, become enormous, but also the heat exchangers and piping must be protected against corrosion and scale buildup caused by the cooling water. This requires maintenance and management, and has the disadvantage that both initial equipment costs and maintenance costs increase significantly.

In order to overcome such problems with conventional canned motor pumps, it is necessary to improve the heat resistance of the canned motor. In this case, it is necessary to increase the heat resistance of the motor components, and what is particularly important is the dielectric strength of the windings against high temperatures. In conventional canned motors with a general structure, when exposed to a high temperature atmosphere of 200℃ or higher,
The windings and insulation are thermally degraded, weakening their mechanical strength and becoming more susceptible to dielectric breakdown.

From this point of view, the applicant first used synthetic fluorine mica pieces suspended in an organic silicon compound solvent and impregnated and hardened as an insulator for insulating and holding the winding group. By doing this, this type of insulator is produced in a high-temperature atmosphere of 200°C or higher, where some of the fluorine compounds vaporized from the synthetic fluorine mica melt the siloxane from the silicon organic compound and turn it into ceramic, increasing the mechanical strength and dielectric strength of the winding. Based on the knowledge that the winding can be improved, by configuring the winding as a field winding,
We have successfully developed a canned motor pump that has sufficient dielectric strength in high-temperature environments of 300℃ or higher.

In other words, in the high-temperature canned motor pump, a canned motor with improved heat resistance is connected to the pump part via an adapter, and the motor part is thermally isolated, so that the temperature can be lowered from a temperature lower than that generated in the motor part. By configuring a structure in which a part of the high-temperature handling liquid is circulated into the canned motor section via partial external piping as necessary, the heat generated by the motor can be recovered with the handling liquid, and the structure is simple. It contributes to resource and energy conservation, and can easily reduce operating costs.

However, in this type of high-temperature canned motor pump, the outer peripheral wall of the stator assembly in the motor section is exposed to the outside air, so some of the heat generated by the motor is dissipated to the outside air using this outer peripheral wall as a heat transfer surface. The resulting heat loss is also a significant loss from the standpoint of energy saving and economic efficiency.

Therefore, the present inventors have developed a canned motor pump that overcomes the problems of the conventional canned motor pump and can effectively recover all the heat generated by the motor into the handled liquid, further increasing the energy saving effect. As a result of various studies, we installed a jacket on the outer peripheral wall of the canned motor section, and introduced a portion (several percent) of the handled liquid, which was pressurized in the pump section and was lower than the temperature generated in the canned motor section, into this jacket. After all the heat generated by the motor is absorbed by this handled liquid, if the liquid is returned to the suction side of the pump section or the low pressure section of the pump piping system, the heat generated by the motor can be absorbed and absorbed with an extremely simple piping configuration. It has been found that the above-mentioned problems can be solved by making effective use of it efficiently.

Therefore, it is an object of the present invention, in a canned motor pump that uses a canned motor with excellent heat resistance of 300°C or higher, to transfer all of the heat generated by the canned motor internally and externally to the handled liquid, which has a temperature lower than the temperature generated by the canned motor. By absorbing heat and efficiently recovering this thermal energy, a canned motor pump achieves smooth pump operation and reduces the heat load on the handling liquid heating source, contributing to resource and energy savings. is to provide.

In order to achieve the above object, the present invention comprises a canned motor section and a pump section that have a dielectric strength against high temperatures of 200°C or higher, and the heat generated in the canned motor section is transferred to the liquid handled by the pump through its outer peripheral wall. In a canned motor pump, a part of the pump handling liquid, which is lower than the temperature generated in the canned motor section, is passed from the rear side of the impeller of the pump section, through the rotor and stator of the canned motor section, and between the rotor chambers at a predetermined pressure. A circulation system for the handling liquid is configured to prevent the heat energy of the handling liquid absorbed by the pump from dissipating into the atmosphere from the outer peripheral wall of the canned motor section, A jacket having an inlet for supplying a portion of the pump and an outlet communicating with the low pressure side of the pump section is arranged around the jacket, and the thermal energy of the handling liquid obtained from the outlet of this jacket is transferred to the handling liquid obtained from the circulation system. The present invention is characterized in that the temperature of the liquid handled by the pump is maintained at the same level as the liquid temperature at the inlet of the pump section or is increased by recovering the heat energy together with the pump section. That is, in the present invention, the jacket is provided not only to simply cool the motor section, but also to actively recover heat.

In the canned motor pump described above, it is preferable to attach the jacket to the outer peripheral wall so as to surround the entire core of the stator assembly.

In addition, a pipe communicating with the liquid supply port of the jacket is connected to a part of the discharge pipe part of the pump part, and a pipe led out from the liquid discharge port of the jacket is connected to a part of the suction pipe part of the pump part. It is suitable if

The canned motor part, which has improved dielectric strength against high temperatures of 200°C or higher, is constructed by impregnating and hardening the field windings with an insulation impregnating agent made of a special silicone resin filled with fluorine mica.

In addition, the canned motor section communicates the outer periphery of the impeller of the pump section with the front rotor chamber, and the rear rotor chamber communicates with the back side of the impeller of the pump section via an internal conduit provided on the rotor shaft. It is preferable to configure a system.

Furthermore, if the pump part and the canned motor part are connected by an adapter having a liquid passage that communicates with each other, it is suitable for assembly and disassembly.

Next, embodiments of the canned motor pump according to the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 2 shows an embodiment of the canned motor pump according to the present invention, in which reference numeral 50 indicates a pump section, 52 indicates a canned motor section, and the pump section 5
0 and the motor section 52 are connected to each other through an adapter 54 so as to be compatible with each other.

The pump section 50 includes a suction pipe section 60 and a discharge pipe section 6 that communicate with a pump chamber 58 in which an impeller 56 is provided.
2, and the impeller 56 is attached to the extended end of the rotor shaft 64 of the motor section 52. On the other hand, the motor section 52 includes a stator assembly 66 and a rotor assembly 68. The rotor shaft 64 is supported by a front bearing 70 and a rear bearing 72, respectively. A rotor chamber 76 is formed.

Further, a liner disk 78 is provided at the joint between the pump section 50 and the adapter 54, and the end of the liner disk 78 on the rotor shaft 64 side is extended,
The adapter 5 is fitted into the bearing support member 80.
A liquid passage path 82a, 82b divided into four parts is formed. Therefore, a through hole 84 is formed in the liner disk 78 at a position on the outer peripheral side of the impeller 56, and this through hole is communicated with the one liquid passage 82a. On the other hand, the axial center of the rotor shaft 64 is drilled in the axial direction to form an internal conduit 8.
A through hole 90 is formed in an end nut 88 provided at the rear end of the rotor shaft 64 to communicate the internal conduit 86 with the rear rotor chamber 76, and an end nut 88 is provided at the front end of the rotor shaft 64. Through hole 9 in spacer 92
4 is bored to communicate the internal conduit 86 with the other liquid passage 82b provided in the adapter, and this liquid passage 82b is connected to the low pressure side of the pump section 50, that is, a balance hole 96 bored in the impeller 56. It communicates with the suction port side of the impeller 56 through.

In this way, the front rotor chamber 74 introduces a portion of the handling liquid having a temperature lower than the temperature generated in the canned motor section 52 from the pump section 50.
A through hole 98 is bored at 0. Moreover, a through hole 10 is provided on the inner circumferential surface of the front bearing 70 for guiding a portion of the handling fluid introduced into the front rotor chamber 74 for lubrication.
Cut 0. The handling liquid introduced into the front rotor chamber 74 is introduced into the rear rotor chamber 76 via the rotor-stator gap 102, and a through hole 106 is formed in the bearing support member 104 that supports the rear bearing 72.
An internal conduit 8 formed in the rotor shaft 64 by drilling a
It is configured to communicate with a through hole 90 connected to 6.
Moreover, a through hole 108 is also cut in the inner peripheral surface of the rear bearing 72 to guide a portion of the handling liquid introduced into the rear rotor chamber 76 for lubrication.

On the other hand, in the canned motor used in the present invention, the insulation treatment of the field winding is strengthened in order to improve heat resistance, that is, dielectric strength against high temperatures, compared to conventional canned motors. That is, the copper wire used as the winding conductor is a glass winding wire whose surface is nickel-plated and further coated with glass insulation to prevent oxidation due to heat. In addition, an inorganic adhesive laminated mica plate is used for the wedge, and a laminated mica plate using a minimum amount of special silicone resin adhesive is used for the flexible insulation sheet. Then, small pieces of synthetic fluorine mica with a thickness of 5 mm or less and a diameter of 0.1 to 5 μm are added to a silicon organic compound solvent in a weight ratio of 1:1 or more as an insulating impregnating agent and coil end molding material to insulate between windings. A suspension of an organic solvent, such as a mixed solvent of xylene, butyl cellosolve, and cellosolve acetate, is used, and the winding wire is impregnated with this and cured.

In this way, by insulating the field winding, the insulating impregnant can remove some fluorine compounds, such as SiF ₄ and KF, which vaporize from the fluorine-containing mica in a high-temperature atmosphere of 200°C or higher, from silicon organic compounds. The siloxane can be melted to form a ceramic to improve the mechanical strength and dielectric strength of the winding.

Therefore, the canned motor configured in this manner has sufficient dielectric strength even when exposed to a high temperature atmosphere of 300° C. or higher, and can be operated as a canned motor pump.

The above configuration shows the basic configuration of one embodiment of the previously developed canned motor pump. In the present invention, in the canned motor pump having the above configuration, a jacket 116 is disposed on the outer peripheral wall 114 portion surrounding the iron core portion 112 of the stator assembly 66, and the pump is connected to the liquid supply port 118 provided in the jacket 116. A pipe 120 led out from a part of the discharge pipe section 62 of the section 50 is connected in communication with the liquid discharge port 12 provided in the jacket 116.
This is characterized in that a pipe 124 led out from 2 is connected to a part of the suction pipe part 60 of the pump part 50.

With this configuration, the generated heat radiated outward from the iron core 112 of the stator assembly 66 using the outer peripheral wall 114 as a heat transfer surface is transferred to the jacket 11.
Heat is absorbed by a portion of the handled liquid, which is lower in temperature than the generated temperature of the canned motor section similar to the above, whose pressure is increased by the pump section 50 introduced into the pump 6, and the temperature of the handled liquid is increased. can all be sent back to the pump suction side.

On the other hand, inside the canned motor section 52, a part of the handling liquid sucked into the pump section 50 is
Liner disk 78 from the back of the outer periphery of the impeller 56
The liquid is introduced into the front rotor chamber 74 through a through hole 84 provided in the liquid passage 82 a and a through hole 98 provided in the bearing support member 80 . A portion of the handling liquid introduced into the front rotor chamber 74 is transferred to the front bearing 7
0 lubrication, the through hole 100 and the liquid passage 82b
and circulates to the low pressure side of the pump section 50 via the balance hole 96 of the impeller 56. Additionally, most of the handling liquid introduced into the front rotor chamber 74 passes through the rotor-stator gap 102 to the rear rotor chamber 74.
It absorbs the heat generated by the motor. In addition,
A portion of the handling fluid guided into the rear rotor chamber 76 is circulated and supplied to the through hole 108 in order to lubricate the rear bearing 72. In this way, the heated handling liquid that has reached the inside of the rear rotor chamber 76 is transferred to the through hole 106 provided in the bearing support member 104, the through hole 90 provided in the end nut 88, and the rotor shaft 64.
It circulates to the low pressure side of the pump section 50 through the internal conduit 86 provided in the spacer 92, the passage hole 94 provided in the spacer 92, the liquid passage 82b, and the balance hole 96 of the impeller 56.

Therefore, in the present invention, two pumps are used in a single pump.
It would be understandable to provide two hot liquid circulation systems.

In this way, according to the canned motor pump according to the present invention, the heat generated in the motor section 52 is absorbed by the pump handling liquid, which is lower in temperature than the temperature generated in the motor section, inside and outside the motor section, and is transferred to the pump system. It can be recovered. Moreover, in this case, the amount of the handled liquid circulating in the canned motor section 52 is about several percent of the amount of liquid in the suction section of the pump section, so even if the handled liquid that has absorbed heat is returned to the suction side of the pump, the amount of liquid in the suction section will be reduced. Since it has almost no effect on the overall temperature rise, the canned motor section 52
The difference between the temperature of the pump and the liquid temperature of the pump suction section is maintained sufficiently, and the cooling effect of the canned motor section can be sufficiently maintained. Therefore, according to the canned motor pump according to the present invention, it is possible to effectively cool the canned motor part, and to easily realize a pump system for high-temperature handling liquid that is excellent in economy without energy loss.

In the canned motor pump according to the present invention, as a means for supplying the pump handling liquid to the jacket 116 and circulating it to the pump system,
Without being limited to the embodiments described above, for example, as shown in FIG.
A pipe 120 communicating with 8 can also be connected and arranged. In addition, the liquid outlet 122 of the jacket 116
As shown in FIG.
It is also possible to connect to 8.

As is clear from the above-mentioned embodiments, when the canned motor pump according to the present invention is used as a high-temperature liquid delivery pump, all the heat generated from the motor can be absorbed into the handled liquid, so there is no energy loss. In addition, the heat load on the heating source (fuel cost for boiler or heater, etc.) can be reduced, and highly economical pump operation can be achieved.

Although the preferred embodiments of the present invention have been described above, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional side view of the main parts of a conventional canned motor pump for high-temperature handling liquids, FIG. 2 is a cross-sectional side view of the main parts of an embodiment of the canned motor pump according to the present invention, and FIG. FIG. 7 is an explanatory diagram of a piping configuration showing another embodiment of the invention canned motor pump. 10... Pump section, 12... Canned motor section, 14... Adapter, 16... Auxiliary impeller,
18...Pressure equalization hole, 20...Main impeller, 22...
Rotor chamber, 24... Stator assembly, 26... Heat exchanger, 28... First circulation tube, 30... Pipe, 32... Second circulation tube, 34... Rear bearing housing, 36... Rear bearing, 38... Stator can, 40... Rotor assembly, 42... Rota can, 44... Front bearing, 46... Front bearing housing, 50... Pump section, 52
... Motor section, 54 ... Adapter, 56 ... Impeller, 58 ... Pump chamber, 60 ... Suction pipe section, 6
2...Discharge pipe section, 64...Rotor shaft, 66...Stator assembly, 68...Rotor assembly, 70...Front bearing, 72...Rear bearing, 74...
Front rotor chamber, 76...Rear rotor chamber, 78...
Liner disk, 80...bearing support member,
82...Liquid passage, 84...Through hole, 86...Internal conduit, 88...End nut, 90...Through hole, 92
...Spacer, 94...Through hole, 96...Balance hole, 98...Through hole, 100...Through hole, 102...
Between rotor and stator, 104...Bearing support member, 106...Through hole, 108...Through hole, 112
... Iron core part, 114 ... Outer peripheral wall, 116 ... Jacket, 118 ... Liquid supply port, 120 ... Piping,
122...liquid discharge port, 124...piping, 126...
...Discharge piping, 128...Handled liquid supply tank.

Claims (1)

[Scope of Claims] 1. A canned motor pump that is composed of a canned motor section and a pump section that have dielectric strength against high temperatures of 200°C or higher, and that absorbs the heat generated in the canned motor section into the liquid handled by the pump through its outer peripheral wall. In the above, a part of the pump handling liquid having a temperature lower than the generation temperature of the canned motor section is passed from the rear side of the impeller of the pump section through the rotor and stator of the canned motor section and between the rotor chambers at a predetermined pressure to be absorbed. A circulation system for the handling liquid is configured to prevent the thermal energy of the liquid from dissipating into the atmosphere from the outer peripheral wall of the canned motor section, and an inlet for supplying another part of the pump handling liquid to the outer peripheral wall of the canned motor section. and an outlet communicating with the low pressure side of the pump section, the thermal energy of the handling liquid obtained from the outlet of the jacket is transferred to the pump section together with the thermal energy of the handling liquid obtained from the circulation system. 1. A canned motor pump characterized in that the temperature of the liquid handled by the pump is maintained at the same level as the temperature of the liquid at the inlet of the pump section or is raised. 2. The canned motor pump according to claim 1, wherein the jacket is attached to the outer peripheral wall so as to surround the entire iron core of the stator assembly. 3. In the canned motor pump according to claim 1, the pipe communicating with the liquid supply port of the jacket is connected to a part of the discharge pipe part of the pump part, and the pipe is led out from the liquid discharge port of the jacket. A canned motor pump that is connected to a part of the suction pipe section of the pump section. 4. The canned motor pump according to claim 1, wherein the canned motor portion is formed by impregnating and hardening the field winding with an insulating impregnating agent made of a special silicone resin filled with fluorine mica. 5. In the canned motor pump according to claim 1, the canned motor section communicates the outer circumference of the impeller of the pump section with the front rotor chamber,
A canned motor pump in which the rear rotor chamber is connected to the back side of the impeller of the pump section via an internal conduit provided on the rotor shaft, forming a circulation system for the handled liquid. 6. The canned motor pump according to claim 1, wherein the pump part and the canned motor part are connected by an adapter having a liquid passage that communicates with each other.